The following abbreviations are herewith defined:    3GPP third generation partnership project    ARQ automatic repeat request    F-DPCH fractional dedicated physical channel    E-DCH enhanced dedicated channel    E-DPCCH enhanced dedicated physical control channel (uplink L1 information concerning data rate)    E-DPDCH enhanced dedicated physical channel (uplink data channels)    E-HICH E-DCH hybrid ARQ indicator channel (in downlink)    E-AGCH E-DCH absolute grant channel (in downlink)    HS high speed    HSUPA high speed uplink packet access    L1 Layer 1 (physical)    Node-B base station    PRACH physical (or packet) random access channel    RACH random access channel    TCP transport control protocol    UE user equipment    WCDMA wideband code division multiple access
This section is intended to provide a background or context to the invention that is recited in the claims. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, what is described in this section is not prior art to the description and claims in this application and is not admitted to be prior art by inclusion in this section.
Communication systems and networks, such as, for example, mobile telephone or cellular systems have greatly expanded and are in widespread use and enjoy increased popularity as the communication device of choice. One reason for such popularity is the mobility of users to travel from area-to-area and receive service. These communication devices typically establish end-to-end communication through a network. In its most simplistic terms, unlike hard-wired “land” communications, mobile telecommunication devices or user equipment (UE), such as, cellular telephones must establish a connection to a serving controller coupled to a network to carry communication data. Accordingly, a procedure is carried out between the UE and network via a network element (e.g., Node B) to establish a connection. The operation, features and advantages of cellular type communication and devices are well known.
An uplink access channel, broadly referred to herein as the random access channel (RACH), is one typically utilized by user equipment (UE) for initial access signaling to a network in instances when no dedicated or shared physical channel connection is currently established. For example, the RACH can be used for initial cell access after the UE powers-on. The RACH can be used to perform a location update after the UE moves from one location to another, for initiating a call or for user data transmission. The RACH capture procedure specified by the 3rd Generation Partnership Project (3GPP) requires the UE to transmit a series of access preambles each with increasing transmit power for each access preamble attempt. Each of the access attempts is separated by an appropriate waiting time of sufficient duration to allow detection of an acknowledgment indication (AI) signal from the receiving station Node B.
It is noted that for RACH Release 99 the data rates are very low. More specifically, the practical instantaneous data rate is 16 kbps (16 thousand bits per second, or 320 bits in 20 ms) and effectively <10 kbps when preamble power ramping is taken into account. Further, in the event of a failed RACH transmission the retransmission delays are significant, on the order of seconds.